Roof area and pitch calculator



July 6, 1937. M. o. BoGARir 2 086,349

ROOE AREA. ,AND PITCH CALCULATOR Filed June 10, 1936 Patented July 6, 1937 UNHTEE STATES career (ii-i i 'lfiE Application .l'une l0,

4 @laims.

The present invention relates to means for quickly and accurately determining the pitch and area of a triangular shaped roof, for the purpose of estimating the cost of shingling, painting, etc.

The primary object of the present invention is to provide a device which may be used to ascertain the pitch and area of a triangular shaped roof with the minimum amount of arithmetical 1O calculation. Another object of the present inerror involved in arithmetical computation.

vention is to provide a device for the aforesaid purpose which will provide ready and accurate calculations for the roof area and pitch and will thus save time and eliminate the chance of A further object of the invention is to provide a device of the character referred to which is simple in structure, easy to manipulate and practical in use. Other objects and advantages of the present invention will in part be pointed out hereinafter, and will in part be apparent to those engaged in the art to which the present invention relates.

With the above and other objects in view, the present invention consists of the novel features of construction and arrangement hereinafter more specifically described and illustrated in the accompanying drawing wherein there is shown a preferred embodiment of the invention.

In the accompanying drawing, forming an in tegral part of this specification,

Fig. 1 is a face view of one of the members of my improved device.

Fig. 2 is a face view of the other member of 35 my improved device.

Fig. 3 is a front elevation of the device constructed in accordance with the invention showing the members in relative position when in use.

Fig. 4 is a transverse section taken substan- 40 tially along the line fl.4 of Fig. 3.

Referring now to the drawing wherein like reference characters indicate corresponding parts throughout the several views, the invention comprises two members ill and ii, each being sub- 45 stantially triangular in shape, and preferably made of cardboard, celluloid or other suitable material. The member II is superposed upon the member l0 as shown in Fig. 3, and the two members are pivotally connected by an eyelet I2,

50 in such manner that the center of the eyelet cor- 55 normal superposed position the edges of the up- 1936, Serial No. 84,407

per member i! coincide with the edges of the lower member it except that the left hand side of the upper member is cut away from its apeX at a more acute angle so as to expose a portion of the face of the lower member. The angle formed between the sides of the member ii] is substantially equivalent to the minimum angles generally formed between the sides of a pitched roof. This angle is approximately 60. The eyelet i2 is preferably but not necessarily about 5% in diameter and provides a sight aperture it for the purpose hereinafter described.

The face of the member i9 is divided into sectors by radial lines emanating from the center of the aperture 53. Each line represents a roof pitch which is indicated to the left of the line in the block located at the upper portion of the sector. It will be observed in Fig. 1 that the device provides for pitches ranging from to A which are the normal pitch limits for modern roof construction. To the left of each pitch line there is also indicated a series of figures repre senting roof areas for that particular pitch, the smallest figure being located near the upper portion of the sector and the figures being increased as they are removed therefrom.

The face of the member i i is provided with a series of figures each representing the base area of a roof at the eaves. These figures are indicate-d adjacent to the left hand side of the member ii and are so arranged as to register with the corresponding roof area figures indicated on the member Hi When the members are assembled.

When the two members i0 and ii are in normal superposed position the left hand side of the member H coincides with the pitch line on the face of the member it. In that position the device gives the roof area figures for a 7 pitch roof corresponding to the respective base area figures with which they register. The base area at the eaves is read upon the member I i and the corresponding roof area is read upon the member ii]. In like manner the various relative positions of the two members will give the various roof areas corresponding to the various base areas for various pitches of a roof.

To illustrate the use of the present invention let us assume it is desired to ascertain the roof area and pitch of a given roof of a house which measures 28 x 38' with a one foot overhang of the roof on all sides. First, it is necessary to obtain the level area of the base of the roof at the eaves by arithmetical computation. The outside dimensions of the base of the roof would be 30 feet and feet, and the level area would therefore be 30 i0 which equals 1200 square feet. The operator then stands at a distance of approximately to '75 feet from the house, holding the device vertically in front of him and he sights the apex of the roof through the sight aperture E3. The two members l6 and H are then spread by moving them relatively about the pivoting point until the angle between the outside edges appears to correspond with the angle between the sides of the roof. The device is then read in that position of the two members. Let us assume that the two members are in the position shown in Fig. 3 wherein the left hand side of the member li coincides with the second line from the left hand side of the member it). The pitch of the roof would then be and the roof area in square feet would be the figure on the member iii which registers with the figure 1200 on the member ii which in this particular case would be 1920. This operation is performed for the purpose of determining the roof area and pitch of any given roof.

It will be obvious to those engaged in the art to which the present invention relates, that the present invention saves considerable time ordinarily consumed in arithmetical computation and that the results obtained thereby are more accurate. The invention may also have application to other purposes not presently contemplated.

Although the present invention is essentially of the construction hereinabove described, it is to be understood that I do not desire to limit myself to the specific structure illustrated and described, for obvious changes may be made in details of construction and arrangement which will come within the scope and spirit of the present invention as outlined in the appended claims.

Having thus illustrated and described my present invention, what I claim as new and desire to secure by Letters Batent is:

1. A device for calculating the pitch and area or a triangular roof, substantially as described, comprising a pair of superposed sectorial shaped members pivotally connected at their apices and having a sight aperture thereat, the face of the lower member being defined by a plurality of radial lines designating various roof pitches, each line being marked with a radial series of figures indicating roof areas, and the face of the up per member being marked with a radial series of figures adjacent one side thereof indicating base areas, the figures on the upper member being adapted to register with corresponding figures on the lower member when the two members are moved relative to each other.

2. A device for calculating the pitch and area of a triangular roof, substantially as described, comprising a pair of superposed sectorial shaped members pivotally connected at their apices and having a sight aperture thereat, the radial angle of the upper member being slightly smaller than the radial angle of the lower member, the face of the lower member being defined by a. plurality of radial lines designating various roof pitches, each line being marked with a radial series of figures indicating roof areas, and the face of the upper member being marked with a radial series of figures adjacent one side thereof indicating base areas, the figures on the upper member being adapted to register with corresponding figures on the lower member when the two members are moved relative to each other the calculations being determined by the angle between the outer sides of both members corresponding to the angle between the sides of a roof.

3. A device for calculating the pitch and area of a triangular roof, substantially as described, comprising a pair of superposed sectorial shaped members pivotally connected at their spices and having a sight aperture thereat, the radial angle of the lower member corresponding to the minimum angle between the sides of a roof, the radial angle of the upper member being slightly smaller than the radial angle of the lower member, the face of the lower member being defined by a plurality of radial lines designating various roof pitches, each line being marked with a radial series of figures indicating roof areas, and the face of the upper member being marked with a radial series of figures adjacent one side thereof indicating base areas, the figures on the upper member being adapted to register with corresponding figures on the lower member when the two members are moved relative to each other the calculations being determined by the angle between the outer sides of both members corresponding to the angle between the sides of a roof.

l. A device for calculating the pitch and area of a triangular roof, substantially as described, comprising a pair of superposed sectorial shaped members pivotally connected at their apices and having a sight aperture thereat and adapted for relative axial movement, the lower member carrying upon its face indicia for roof pitches and roof areas, the upper member carrying upon its face indicia for base areas, the two members cooperating to designate roof areas corresponding to base areas for various roof pitches the calculations being determined by the angle between the outer sides of both members corresponding to the angle between the sides of a roof.

MORGAN O. BOGAR'I. 

